Radio Frequency Identification or RFID as name suggests works on radio frequencies. RFIDs were first introduced as option for long lasting identification technology of Bar-coding. Bar coding was in veins of most of the business lines and helped organizations to identify and audit use and supply of products. However RFID is a technology that helped in tracking and positioning real time situation of objects and people and also helped in counting auditing and effectively using objects or people.
RFID is a technology that has travelled from outdoor applications to indoor applications. However, RFID alone is not effective in indoor environment hence it is always integrated with available wireless technologies like Wi-Fi, Bluetooth,UWB or IR.
RFID in indoor location solutions is used to track assets, people and documents. RFID has helped in optimizing use of assets and people, ensuring staff and valuable asset security and effective management of organizational operations. Also on cost front, RFID is becoming very cost effective and user friendly technology.
This is why RFID is one of the preferred technologies by various sectors like Healthcare, B&FS, Insurance, Legal, Manufacturing industries and other sectors like education, social networking.
RFID systems make use of four frequency bands: LF (125 kHz), HF (13.56 MHz), UHF (433, 868-915 MHz) and microwave (2.45GHz, 5.8 GHz). There are no global public body that governs frequencies used for RFID, however every country has their own standards and regulations.
Components of RFID
RFID systems are consists of tags, antenna and reader
Tags and readers are the main components of an RFID system. The typical reading range is 1-2 meters. A typical RFID tag consists of a microchip attached to a radio antenna mounted on a substrate. The chip can store as much as 2 kilobytes of data. RFID tags come in various forms like chips, labels or cards.
There are two types of tags in RFID.
Passive RFID: RFID tags or Transponders without battery are known as passive RFID tags. These tags don’t have power supply. This is why they are called passive. Passive RFID tags get power from electromagnetic field generated by reader antenna. Radio waves from the reader antenna encounter the coiled antenna within the tag to form a magnetic field energizing the circuits in the tag. The tag then sends the information encoded to transmit back data to the reader.
The advantages of passive RFID are they are cheap and small in size. They have longer life and are maintenance free. They do not need recharging and hence has no issue of power consumption or battery life. Limitations to passive RFID are they can be used for short distances, typically 1-2 meters. Tags remain readable even after the asset to which tag is attached is sold or reuse.
Active RFID: Active RFID tags use power supply like batteries or external power source. These are small transceivers that actively transmit their ID. These tags are active and can use in independent monitoring and control, initiating communications and performing diagnostics. The active RFID tags are little bulky that may limit application. However they have good range and can capture data from 3 to 10 meters.
Readers: RFID reader is a device used to interrogate signals transmitted by RFID tags. The reader has an antenna that emits radio waves; the tag responds by sending back its data. There are two types of RFID readers viz. fixed and mobile.
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